GB482112A - Improvements in typewriting machines - Google Patents

Abstract

482,112. Typewriters. FAIRWEATHER, W. C. (Underwood Elliott Fisher Co.) Sept. 14, 1937, No. 24955. [Class 100 (iv)] Paper-supports; platen-roller brakes; linespacing mechanism.-A detachable platen, associated with a line-spacing detent, and a brake which is effective when the detent is released and vice versa, is retained in open bearings in the carriage by means of pivoted clamps adapted to force the platen firmly into position against the pressure of either the detent or brake. The platen 15 shown in Figs. 1 and 2 is provided with stub-shafts 21 which pass through hubs 22, 37 on the enddiscs 18, the hub 22 and the right-hand stubshaft being mounted in bearings 40 which are received by slots 42 in the end-plates 10 of the platen-carriage. Each bearing is retained by a keeper 47 consisting of a pivoted yoke 55 provided with a screw 57 having a large head 61 engaging the bearing. A link 48 connects the yoke to a finger-lever 46 which is raised to release the keeper. The link and fingerlever form a toggle which normally locks the keeper. Accidental movement of the fmgerlever is prevented by co-operation of a spring- urged locking-sleeve 67 with a hole in the finger-lever. When the locking-sleeves are pulled outwards, the finger-levers can be raised to release the keepers and thereby permit detachment of the platen. On return of the finger-levers, the locking-sleeves are cammed outwards, and then return automatically into locking position. The line-spacing wheel 25 co-operates with a pawl 83 formed on a pivoted arm 28 carried by a pivoted arm 27 operated by the line-spacing lever, the arms 27, 28 being arranged below the left-hand stub-shaft 21, so as to permit detachment of the platen. Overthrow of the pawl is prevented by cooperation of a pin on the arm 28 with a nose on the arm 27. Line-spacing is regulated by means of a finger-lever 87 having a pin 86 co-operating with the pawl. The linespacing wheel co-operates with a detentroller 98 carried by a pivoted arm 99 having a finger 102 abutting on a spring 100 which is mounted on a bracket 101 and is provided with an adjusting-screw 101a. The detentroller is releasable by depressing a fingerlever 106 in connection with a link 108 having a slot 101 engaging a pin 110 on the arm 99. A coupling for the line-spacing wheel comprises a brake-shoe 32 which co-operates with a drum 30 on the line-spacing wheel. When the detent-roller is released, a brakespring 103, secured to a bracket 104 on the arm 99, is pressed against the drum 30, to prevent accidental movement of the platen. The spring 103 may be provided with a frictioncoating.